This reminds me of a secondary anti cross argument used in the Babylon The Great Has Fallen book where the fact that Babylonians would scratch a 't' mark to represent their god Tammuz, somehow reinforced the notion that the cross was pagan.
The thing to keep in mind about this ridiculous non-issue is that the cross is a very simple geometric symbol. Chimpanzees and even elephants have been given paint brushes and been known to paint crosses* and spirals and other abstract designs.
SCrosses and spirals are pagan symbols. Does this mean that these semi-sentient animals are being possesed by the Devil in what would obviously be a pointless exercise in mocking Mr "I'm not a Pagan" Jehovah?
Bottom line. The cross is such a simple geometric design, that it is a meaningless and trivial coincidence to find it in "pagan" (Read non Hebrew Scripture) cultures.
Villabolo
http://books.google.com/books?id=qEf4OkurjPkC&pg=PA177&lpg=PA177&dq=chimpanzees+painting+cross&source=bl&ots=ZxPMXhbQws&sig=FRaYANSs6BMAR8Ggd5HH7ig6Kl4&hl=en&ei=UbhITdr5GY7EsAOBlvmcCg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CCMQ6AEwAQ#v=onepage&q=chimpanzees%20painting%20cross&f=false